1. Field of the Invention
The present invention relates to a method for eliminating crosstalk (coupling noise), and in particular to a method for eliminating crosstalk in a metal programmable read only memory.
2. Description of the Related Art
Typically, read only memories (ROMs) are embedded in system-on-chips (SoCs) for storing codes and wave tables. For much higher speed, large capacitance and shortened marketing time, there has been a trend to gradually use embedded read only memories in SoCs. In the prior art, when a word line is activated, crosstalk between bit lines will cause voltage drops to a selected bit line.
As shown in FIG. 1, BL-A1 and BL-A2 are bit lines with code patterns for reading a logic level “0”. The voltage of BL-D (for reading a logic level “1”) is larger than a reference voltage VREF, and then, it is detected as a logic level “1”; the voltage of BL-V1 (for reading a logic level “1”) is smaller than the reference voltage VREF and under the influence of the crosstalk from BL-A1, and it is detected as a logic level “0”, resulting in a read error in a high-speed metal read only memory.
At present, there is still no method to resolve the problems of crosstalk caused by the above-stated code pattern dependence and read failures in a high-speed metal programmable read only memory.